1. Multi-set designs — designs having blocks with repeated elements;Assaf;Congr. Numer.,1985
2. Balanced n-ary designs: a combinatorial survey and some new results;Billington;Ars Combin.,1984
3. Balanced ternary designs with block size three. any Λ and any R;Billington;Acquationes Math.,1985
4. The number of repeated blocks in balanced ternary designs with block size three;Billington;J. Combin. Math. Combin. Comput.,1989
5. R.A.R. Butler and D.G. Hoffman, Intersections of group divisible triple systems. Ars Combin. to appear.